Tea tree oil, or melaleuca oil, is a pale yellow color to nearly colorless and clear essential oil with a fresh camphoraceous odor. Tea tree oil composition, as per ISO 4730 (2004) is as follows: terpinen-4-ol 30-48%; γ-terpinene 10-28%; α-terpinene 5-13%; 1,8-Cineole 0-15%; α-terpinolene 1.5-5%; α-terpineol 1.5-8%; α-pinene 1-6%; and p-cymene 0.5-8%. For sake of clarity, the terms Tea tree oil and TTO will interchangeably refer hereinafter the various possible TTO compositions as a whole, and to each of its ingredients separately.
Many patents disclose the use of TTO in medicine, some of the recent ones are US 20120009284, Antimicrobial composition and method for using same; US 20110293757, Compositions comprising tea tree oil and methods for the prevention and treatment of cancer; US 20100273870, Compositions and methods for treating demodex infestations; US 20100247376, Antibacterial toothbrush spray; US 20100178284, Composition for the skin, specifically for inhibiting ingrown hair; US 20100173007, Compositions and methods for treating skin conditions in mammals; US 20100056430, Treatment and method for eliminating or reducing foot odor etc.
TTO is known to be active against Staphylococcus aureus, including MRSA. TTO is less successful for application in the nose. Also, there is clinical evidence that topical dermatological preparations containing tea tree oil may be more effective than conventional antibiotics in preventing transmission of CA-MRSA. Recent studies support a role for the topical application of TTO in skin care and for the treatment of various diseases and conditions. TTO appears to be effective against bacteria, viruses, fungal infections, mites such as scabies, and lice such as head lice. In the treatment of moderate common acne, topical application of 5% TTO has shown an effect comparable to 5% benzoyl peroxide, albeit with slower onset of action. TTO is a known antifungal agent, effective in vitro against multiple dermatophytes found on the skin. In vivo, shampoo with 5% tea tree oil has been shown to be an effective treatment for dandruff due to its ability to treat Malassezia furfur, the most common cause of the condition. One clinical study found that 100% TTO administered topically, combined with debridement, is comparable to clotrimazole in effectiveness against onychomycosis, the most frequent cause of nail disease. The effectiveness of topical tea tree oil preparations for the treatment of the yeast infection Candidiasis is supported by its ability to kill Candida in vitro. There is some very limited research that has shown that TTO may have topical antiviral activity, especially against the herpes virus (cold sores), chicken pox, shingles blisters, etc. One study has shown a 5% tea tree oil solution to be more effective than commercial medications against the scabies mite in an in vitro situation.
Nevertheless, despite a remarkable clinical efficiency suggested to TTO, its acute irritation hinders its daily use at high concentrations. Hence, according to the American Cancer Society: “Tea tree oil is toxic when swallowed. It has been reported to cause drowsiness, confusion, hallucinations, coma, unsteadiness, weakness, vomiting, diarrhea, stomach upset, blood cell abnormalities, and severe rashes. It should be kept away from pets and children.” A small number of people experience allergic contact dermatitis as a reaction to dermal contact with TTO. In an Italian study of 725 consecutive patients, patients were patch tested with undiluted, 1%, and 0.1% TTO. For undiluted TTO, nearly 6% of the patients observed positive reactions of skin irritation. Only one of 725 patients observed a positive reaction of skin irritation with the 1% dilution. None of the 725 patients observed adverse reactions with the 0.1% dilution. Allergic reactions may be due to the various oxidation products that are formed by exposure of the oil to light and/or air. Moreover, external application of TTO undiluted and/or at inappropriate high doses has been associated with toxicity, including death, in cats and other animals, due to ingestion during grooming. A highly disputed case study reported in The New England Journal of Medicine concluded that repeated topical exposure of lavender and tea tree oils may have caused prepubertal gynecomastia in three young boys, see Henley, Derek V.; Lipson, Natasha; Korach, Kenneth S.; Bloch, Clifford A. (2007). “Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils”. New England Journal of Medicine 356 (5): 479-85. The study involved just three individuals and found lavender to be the only common ingredient used by the boys in the study. While all three cases involved the use of products containing lavender oil as an ingredient, only one boy also used products containing TTO. It was noted that in all cases, the prepubertal gynecomastia reversed after several months. If used in concentrations below 4% or particularly below 0.25%, TTO may fail to kill bacteria and create selection pressure, which may result in them becoming less sensitive to tea tree oil and even some antibiotics in vitro. Undiluted tea tree oil can cause some hearing loss when used in the ears of animals; however, a 2% concentration has not been shown to have any lasting effect. It is not known whether the same is true for humans.
Hence, as one can see TTO efficiency in treating skin conditions increases from above approximately 0.25%, whilst its irritation is found concentration greater than 0.1%.
Skin treatment by hypertonic solutions and compositions thereof are known in the art. As an example, WO/2009/125383, A MEDICAL COVERING FOR HEALING WOUNDS AND SKIN DISEASES, which is incorporated herein as a reference, discloses a medical covering used for dermatological diseases and topical pathogeneses. The range of this treatment and the time required for achieving a complete cure is moderate.
Use of honey in the cosmetic industry in known in the art. Hence for example, U.S. Pat. No. 5,965,145 discloses use of 0.1 to 10 weight percent honey as keratolytic agent for improving the radiance and the complexion of the skin and treating wrinkles U.S. Pat. No. 5,017,367 discloses a cosmetic composition wherein honey present is in an amount between 0.005 to 0.01 parts per 1 part carrier medium. U.S. Pat. No. 6,551,606 discloses a cosmetic product that contains enzymes and has an intensive skin action, especially a regenerative effect The inventive cosmetic product contains 0.01 to 5 wt. % of a concentrate of the coconut milk of Cocos nucifera, containing peroxidase, lipase and protease; 0.1 to 10 wt. % of a plant milkwater, and 0.01 to 5 wt. % of a glycerol extract of a mixture consisting of honey, rice hulls, rice hull oil and/or rice germ oil; with the remainder consisting of cosmetic auxiliary agents, active agents and carrier substances.
The use of honey and its alternatives in combination with TTO was rarely discussed. U.S. Pat. No. 5,738,863 “Honey bee repellent composition comprising tea tree oil” discloses a social stinging insect repellent composition comprises effective repelling amounts of tea tree oil and benzaldehyde. U.S. Pat. No. 7,147,876 “Compositions for removal of toxins” discloses a medicinal or cosmetic composition comprising Aloe vera in combination with at least one vitamin, a minerals concentrate, an organic oils concentrate, at least one Chinese Herb, at least one essential oil and at least one spice. The invention shows, in one of its embodiments, that the Aloe vera-based composition may also comprise a honey product such as royal jelly or bee propolis. US20110135746 “Protective lip balm composition” discloses a lip balm formulations which comprise a combination of anti-bacterial, anti-viral, and anti-fungal substances, including: bees wax, cocoa butter, Shea butter, Jojoba oil, Naroli oil, myrrh, tea tree oil, lavender oil, Blue Moroccan chamomile, and vitamin E and, optionally, Manuca honey and Aloe vera either singularly or together with the other ingredients.
Hence, a cost effective non skin irritating TTO-based therapeutic composition useful for cosmetics and both veterinary and human medicine which is characterized by a wide spectrum of effective biocidic and dermal action and yet is generally regarded as safe and non-irritant is still a long felt need.